This article provides detailed explanations of the Lesson Reports available in PPO:
The report includes all the fields on the Lessons entity for all lesson records and projects. If the “Include Project Information” checkbox is selected, the report will also include all the fields on the project entity. This report is only available in datasheet view.
The Lesson Learnt Report shows a list of all the current lessons that have been captured on the respective projects. The report can also be filtered further to only include lessons related to certain projects. This report is available in report view, datasheet view and PDF view.
The lessons learnt report is usually used as part of the project closure meeting.